Ascotis selenaria, a major geometridae moth in citrus trees, annually damages the citrus leaves and fruits. The surface of young citrus fruit were usually fed by 1st larva of A. selenaria after landing or stepping onto the citrus fruits. To protect the larval damages of citrus fruits needs to predict the accurate occurrence time of the 1st larva for spraying. Because larval occurrences is dependent on the oviposition of adult female and the eggs were not found in/on citrus trees, oviposition model of A. selenaria linked with the egg development model will be helpful of protecting larval damages on citrus fruits. Adult longevity, survival and fecundity of A.selenaria was investigated at 13, 16, 20, 24, 28, 30, 32, and 35℃. The longevity decreased as the temperature increased and the female development rates (1/median longevity) were well described by a modified sigmoid model, which was used to calculate the adult physiological age. Description of the total fecundity was used by a non-linear model: The maximum fecundity of A. selenaria was estimated as 2490 eggs and peaked temperature was 19.7℃ according to the fecundity model. The cumulative age-specific oviposition rate and the age-specific survival rate was well described by 2 parameters Weibull function and a reverse logistic curve respectively. Total fecundity model, age-sepecific oviposition model, and age-specific survival model were incorporated into the oviposition model.

The cottony cushion scale, Icerya purchasi Maskell (Hemiptera: Margarodidae), is a destructive pest on citrus. This study was conducted to obtain the stage-specific phenology of I.purchasi for use in field application. The crawlers (hatched nymphs) from the egg sac of overwintered female began to move from late May and peaked in early to mid-June with most crawlers completed the movement till late June. The 1st nymph population peaked in mid June in 1stgeneration and early October in 2ndgeneration. The 2nd nymphs showed peak activity in late July and late October during the 1st and 2nd generation, respectively. The 3rd nymphs peaked in early September in 1st generation, while it kept a plateau without forming a peak after mid October in 2nd generation. The 1st generation adults peaked in mid September, and the tail was overlapped with 2nd generation adult population. Consequently, two life cycles were competed in Jeju area. An average of 20.7% of citrus orchards was infested with I. purchasi with a 3.9% of mean infested trees in Jeju. The present results should be useful in establishing management strategies for I. purchasi in citrus orchards.

The damage of citrus fruit by yellow tea thrips, Scirtothrips dorsalis Hood, was first confirmed in 2008, and has since been one of the serious pests of citrus in Jeju. This was reported on damage symptom on tangor cultivar, Setoka (Tangor Norin No. 8) fruits cultivated in a greenhouse and the characteristic of spatial disttribution of S. dorsalis caught on yellow sticky traps was conducted in three commercial citrus orchards. The feeding habits by S. dorsalis cause rind blemishes on the navel part of fruit. The damage is characterized by being scarped and figure like covered cloud on satsum mandarine fruit, but on by a brown ring of rough russeting that occurs on navel part of Setoka fruit. The season of damage occurrence was from middle of June to late of July. There was a highly significant relationship between the average number of thrips per trap and the maximum number caught on a trap. The overall differences between the linear regression models obtained from mean-variance relationship for each surveyed fields were tested by type Ⅲ error and contrast method. The characteristic of spatial distribution of S. dorsalis was better described by Taylor's power law than Iwao's patchiness regression, and the dispersion index which is the slope (=1.72) of linear regression model showed the aggregated distribution pattern. The sequential sampling stop lines at fixed precision level of 0.20, 0.25 and 0.30 were calculated.

Temperature-dependent development and oviposition component models were developed for Pseudococcus cryptus Hempel (Homoptera: Pseudococcidae). Egg development times decreased with increasing temperature and ranged from 2.4d at 16℃ to 1.0d at 28℃. Total development times of nymphs reared on citrus leaves decreased from 54.9d at 16℃ to 17.4d at 28℃ and 19.3d at 32℃. As P. cryptus showed an ovoviviparous reproductive behavior, the periods of egg and the 1st nymph were combined. By fitting linear models to the data the lower developmental threshold temperatures for egg-1st nymphs, the 2nd nymphs, the 3rd nymphs, and all nymphs combined were calculated as 8.7, 12.8, 13.1, and 12.1℃, respectively. The thermal constants were 198.6, 84.7, 69.8, and 296.3 degree-days for each of the above stages. The non-linear model based on a Gaussian equation, which fits the relationship between development rate and temperature was well for all stages. Adult longevity decreased with increasing temperature and ranged from 80.4d at 16 to 31.3d at 32.0℃. Also, preoviposition and oviposition periods showed a similar pattern with the longevity. P. cryptus had a maximum fecundity of 111 eggs per female at 28℃, which declined to 102.7 eggs per female at 32℃.